CONVENTIONAL AND MODERN CONTROL METHODS FOR DISTILLATION COLUMNS - PREDICTIONS AND OPERATING EXPERIENCE

Previous experience has confirmed that computerized design of control circuitry for distillation columns (DC) is feasible. The method of calculation is based on the mathematical model of the dynamic performance of DCs. Control loop synthesis can be accomplished by conventional methods or by the modal control technique. While the necessary calculations have to be performed on a large computer, the resulting control systems can be implemented with equipment used in contemporary practice. If the type of controller and control loop structure are carefully chosen, as will inevitably happen when employing the modal control technique, then high control amplifications, i. e. , small P bands of 2 K, for example, are permissible without the attendant danger of instability. This leads to a high quality of control.